As Stirling Gallacher left her audition for Coronation Street she was in tears, convinced nerves had got the better of her, she had fluffed her lines and had no chance of landing the role as lawyer Paula.

She had been desperate to impress as she did her screen test alongside Sally Dynevor, who plays Sally Metcalfe, and Brooke Vincent , who plays Sally’s screen daughter Sophie Webster.

Stirling, 47, says: “I thought I’d blown it and I really wanted the job, so I had a bit of cry to be honest.

“I wasn’t as sharp as I wanted to be and I probably fluffed a few times. I felt it wasn’t as perfect as I wanted it to be and I thought they would feel that too.

“There were quite a few other actresses and they all looked right.”

Paula, Sally, Sophie and Isla in the Bistro on Coronation Street

She had been the last actress to be seen and was “extremely nervous” by the time her turn came round.

“It was a long drive home. I had a cry in the car and then another one when I got home. I was just cross with myself.

“I love being an actor and I felt a bit of a responsibility to the family. My husband and I have four kids between us and a mortgage and I need to earn a living, so I really wanted the job.”

But five days later, she got the phone call to say she had landed the role.

Stirling, who played Georgina Woodson in Doctors for six years, says: “I was gob-smacked, as you can imagine. I was very pleased, but it goes to show you’re not always your own best judge.”

Stirling plays lawyer Paula Martin who has been hired by her old school friend Sally to defend her on fraud, bribery and money laundering charges.

At British Soap Awards in 2007 with husband Sean (Image: Getty Images Europe)

Bisexual Paula, a divorcee with two kids, falls for Sally’s daughter Sophie and they embark on a secret affair.

Oblivious of their fling, Sally tries to pair her friend off with her former husband Kevin and Paula’s gay daughter Isla, played by Anna Jobarth, with Sophie.

Sally will discover the truth this week when she walks in on Sophie and Paula. Furious, she sacks Paula on the spot and tells Sophie she doesn’t want her at court either.

Stirling, who previously auditioned for a job on Coronation Street as a love interest of Peter Barlow, says: “Paula absolutely has her eye on the prize with Sophie and she’s one of those people who is very clear about how they feel.

“There’s not much hesitation, because I don’t think she questions her logic or her emotions.

“I like the idea of the age gap in the relationship and it looks like a fascinating storyline, but I have absolutely no idea how viewers will respond.

“From my point of view it looks like a real relationship that nobody should be unhappy with – nobody is taking advantage of anybody – but you never know.”

The scenes where Paula and Sophie kiss for the first time were filmed just a week after Stirling joined the show.

She says: “They’re always awkward, I don’t think kissing people you don’t know very well is easy for anybody, but actually with another woman it feels much more straightforward. Maybe if we were both lesbians it might be more complicated, but as straight women I think it’s much easier and clearer and much more technical.”

Paula and Sophie getting cosy

Despite her 24 years as an actress, Stirling admits to nerves when she started her new job.

She says: “When I saw Peter Gunn, who plays Brian Packham, he said hello and I said, ‘Oh hello, we’ve worked together before, haven’t we?’

“And he looked at me and went, ‘Erm...’ and I went, ‘No, sorry, I only know you off the telly’.”

But she quickly settled in. She says: “The cast are a lovely bunch and very welcoming, particularly Brooke Vincent and Sally Dynevor and they made it very easy, but you still have that lonely, first-day-at-school kind of feeling, because you don’t know people very well and it takes a bit of time to build relationships and get chatting.

“There are lots of people you don’t know and you have to hit the ground running and if you care about doing a good job you put a bit of pressure on yourself. It is nerve-wracking.”

The storyline is set to run for the rest of the year, but Stirling has always taken other work to supplement her income and says landing the Coronation Street role will not change that. She says: “I’ve always had a day job and I’ll still be doing my other jobs, even though I’m on Coronation Street. I do day jobs to secure lean times. I don’t have the luxury of a massive stash of cash.

“I design interiors and I’m also an upholsterer. I wanted something I could do from home.” Stirling lives in Gloucestershire, with her actor husband Sean Gleeson, who was her screen husband in Doctors. They won a Best On Screen Partnership gong at the British Soap Awards in 2007.

The couple have two sons, aged 14 and eight, and Sean has a 22-year-old daughter and an 18-year-old son.

Stirling says: “We’re a mixy-matchy family. I’m very lucky.”

But they sometimes have to supplement their incomes. Sean is also a carpenter and together they restore furniture and buy and sell antiques.

She says: “It’s hard. The moment you’ve got a mortgage and children your priorities are different and acting is not a reliable income.”

Stirling played David Brent’s boss Jennifer Taylor-Clarke in both series of Ricky Gervais’ hit comedy The Office.

As Jennifer Taylor-Clarke in The Office

She says: “I had an IT job at the BBC. I got the job on The Office and my boss said as long as I did the work for him, he didn’t mind when I did it.

“So I’d go to film The Office in the day and go back into my real office at 7.30 in the evening, so I could keep the job for when my contract on The Office finished, so I could carry on paying the mortgage.

“Money is tight, as it is with any working family and we don’t have an extravagant lifestyle. Even a holiday feels like a luxury, because you think, ‘What if there’s no work after this?’

“There are less roles as you get older and what you are prepared to leave your family for changes. If it’s rubbish money for a rubbish role on a rubbish show, I think, ‘Is it really worth leaving the kids for six months for that?’

“I’d rather find a day job and not be absent from my family.” Acting has kept her busy lately, though.

She is in The Festival, a film released last month, and the second series of BBC comedy White Gold.

Coronation Street is not her first soap. After leaving Doctors in 2009, she appeared in EastEnders last year as the Mayor of Walford.

She says: “That was an unexpected job. I thought for the comedy value alone it was worth the gig – it still amuses me to this day.”